Mandel Ngan | AFP | Getty Images

It's the ultimate ripple effect.

disrupted transportation. Everything from air to land to sea came to a halt.

It disrupted power. At the peak, more than 8.5 million houses and businesses along the eastern seaboard lost power. Without power, gas stations became inoperable and that led to traffic jams whenever gasoline was available.

While no storm is ever welcome, Sandy's timing, along with the nor'easter that followed, couldn't be worse for retailers, who are preparing for their busiest time of the year.